Conventionally, there is known a liquid-level detection device that detects a surface level of liquid stored in a container. A liquid-level detection device described in Patent Document 1 includes an annularly-shaped magnet part held by a rotatable body and a magnetoelectric conversion device that detects the density of magnetic flux changing according to the rotation of the magnet part. Moreover, a magnetic shield member made of iron nickel is provided to cover the bottom portion and the outer peripheral surface of the magnet part. Accordingly, the attraction and attachment of metallic foreign matter mixed in the liquid in the container to the magnet part can be restrained. As a result, the accuracy in output of the magnetoelectric conversion device can be stabilized.